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SHOW TABLET

SHOW TABLET

Description

Displays tablet related information.

NOTE

For v3.0 and later, this operation requires the SYSTEM-level OPERATE privilege and TABLE-level SELECT privilege. For v2.5 and earlier, this operation requires the ADMIN_PRIV privilege.

Syntax

Query information of tablets in a table or a partition

SHOW TABLET
FROM [<db_name>.]<table_name>
[PARTITION(<partition_name>, ...]
[
WHERE [version = <version_number>]
[[AND] backendid = <backend_id>]
[[AND] STATE = "NORMAL"|"ALTER"|"CLONE"|"DECOMMISSION"]
]
[ORDER BY <field_name> [ASC | DESC]]
[LIMIT [<offset>,]<limit>]

Parameter

Required

Description

db_name

No

The database name. If you do not specify this parameter, the current database is used by default.

table_name

Yes

The name of the table from which you want to query tablet information. You must specify this parameter. Otherwise, an error is returned.

partition_name

No

The name of the partition from which you want to query tablet information.

version_number

No

The data version number.

backend_id

No

The ID of the BE where the replica of the tablet is located.

STATE

No

The status of tablet replicas.

  • NORMAL: The replica is normal.
  • ALTER: A Rollup or schema change is being performed on the replica.
  • CLONE: The replica is being cloned. (Replicas in this state are not available for use).
  • DECOMMISSION: The replica is being decommissioned.

field_name

No

The field by which the results are sorted. All the fields returned by SHOW TABLET FROM <table_name> are sortable.

  • If you want to display results in ascending order, use ORDER BY field_name ASC.
  • If you want to display results in descending order, use ORDER BY field_name DESC.

offset

No

The number of tablets to skip from the results. For example, OFFSET 5 means to skip the first five tablets. Default value: 0.

limit

No

The number of tablets to return. For example, LIMIT 10 means to return only 10 tablets. If this parameter is not specified, all the tablets that meet the filter conditions are returned.

Query information of a single tablet

After obtaining all tablet IDs using SHOW TABLET FROM <table_name>, you can query the information of a single tablet.

SHOW TABLET <tablet_id>

Parameter

Required

Description

tablet_id

Yes

Tablet ID

Description of return fields

Query information of tablets in a table or a partition

+----------+-----------+-----------+------------+---------+-------------+-------------------+-----------------------+------------------+----------------------+---------------+----------+----------+--------+-------------------------+--------------+------------------+--------------+----------+----------+-------------------+
| TabletId | ReplicaId | BackendId | SchemaHash | Version | VersionHash | LstSuccessVersion | LstSuccessVersionHash | LstFailedVersion | LstFailedVersionHash | LstFailedTime | DataSize | RowCount | State | LstConsistencyCheckTime | CheckVersion | CheckVersionHash | VersionCount | PathHash | MetaUrl | CompactionStatus |
+----------+-----------+-----------+------------+---------+-------------+-------------------+-----------------------+------------------+----------------------+---------------+----------+----------+--------+-------------------------+--------------+------------------+--------------+----------+----------+-------------------+

Field

Description

TabletId

Table ID.

ReplicaId

Replica ID.

BackendId

The ID of the BE where the replica is located.

SchemaHash

Schema hash (randomly generated).

Version

Data version number.

VersionHash

Hash of data version number.

LstSuccessVersion

The last successfully loaded version.

LstSuccessVersionHash

The hash of the last successfully loaded version.

LstFailedVersion

The version of the last failed loading. -1 indicates no version failed to be loaded.

LstFailedVersionHash

The hash of the last failed version.

LstFailedTime

The time of the last failed loading. NULL indicates there is no load failure.

DataSize

Data size of the tablet.

RowCount

The number of data rows of the tablet.

State

Replica status of the tablet.

LstConsistencyCheckTime

The time of the last consistency check. NULL indicates no consistency check was performed.

CheckVersion

The data version on which consistency check was performed. -1 indicates no version was checked.

CheckVersionHash

The hash of the version on which consistency check was performed.

VersionCount

The total number of data versions.

PathHash

The hash of the directory in which the tablet is stored.

MetaUrl

The URL used to query more meta information.

CompactionStatus

The URL used to query data version compaction status.

Query information of a specific tablet

+--------+-----------+---------------+-----------+------+---------+-------------+---------+--------+-----------+
| DbName | TableName | PartitionName | IndexName | DbId | TableId | PartitionId | IndexId | IsSync | DetailCmd |
+--------+-----------+---------------+-----------+------+---------+-------------+---------+--------+-----------+

Field

Description

DbName

The name of the database to which the tablet belongs.

TableName

The name of the table to which the tablet belongs.

PartitionName

The name of the partition to which the tablet belongs.

IndexName

The index name.

DbId

The database ID.

TableId

The table ID.

PartitionId

The partition ID.

IndexId

The index ID.

IsSync

Whether data on the tablet is consistent with table meta. true indicates data is consistent and the tablet is normal. false indicates data is missing on the tablet.

DetailCmd

The URL used to query more information.

Examples

Create table test_show_tablet in the database example_db.

CREATE TABLE `test_show_tablet` (
`k1` date NULL COMMENT "",
`k2` datetime NULL COMMENT "",
`k3` char(20) NULL COMMENT "",
`k4` varchar(20) NULL COMMENT "",
`k5` boolean NULL COMMENT "",
`k6` tinyint(4) NULL COMMENT "",
`k7` smallint(6) NULL COMMENT "",
`k8` int(11) NULL COMMENT "",
`k9` bigint(20) NULL COMMENT "",
`k10` largeint(40) NULL COMMENT "",
`k11` float NULL COMMENT "",
`k12` double NULL COMMENT "",
`k13` decimal128(27, 9) NULL COMMENT ""
) ENGINE=OLAP
DUPLICATE KEY(`k1`, `k2`, `k3`, `k4`, `k5`)
COMMENT "OLAP"
PARTITION BY RANGE(`k1`)
(PARTITION p20210101 VALUES [("2021-01-01"), ("2021-01-02")),
PARTITION p20210102 VALUES [("2021-01-02"), ("2021-01-03")),
PARTITION p20210103 VALUES [("2021-01-03"), ("2021-01-04")),
PARTITION p20210104 VALUES [("2021-01-04"), ("2021-01-05")),
PARTITION p20210105 VALUES [("2021-01-05"), ("2021-01-06")),
PARTITION p20210106 VALUES [("2021-01-06"), ("2021-01-07")),
PARTITION p20210107 VALUES [("2021-01-07"), ("2021-01-08")),
PARTITION p20210108 VALUES [("2021-01-08"), ("2021-01-09")),
PARTITION p20210109 VALUES [("2021-01-09"), ("2021-01-10")))
DISTRIBUTED BY HASH(`k1`, `k2`, `k3`);
  • Example 1: Query information of all the tablets in the specified table. The following example excerpts information of only one tablet from the return information.

        mysql> show tablet from example_db.test_show_tablet\G
    *************************** 1. row ***************************
    TabletId: 9588955
    ReplicaId: 9588956
    BackendId: 10004
    SchemaHash: 0
    Version: 1
    VersionHash: 0
    LstSuccessVersion: 1
    LstSuccessVersionHash: 0
    LstFailedVersion: -1
    LstFailedVersionHash: 0
    LstFailedTime: NULL
    DataSize: 0B
    RowCount: 0
    State: NORMAL
    LstConsistencyCheckTime: NULL
    CheckVersion: -1
    CheckVersionHash: 0
    VersionCount: 1
    PathHash: 0
    MetaUrl: http://172.26.92.141:8038/api/meta/header/9588955
    CompactionStatus: http://172.26.92.141:8038/api/compaction/show?tablet_id=9588955
  • Example 2: Query information of tablet 9588955.

        mysql> show tablet 9588955\G
    *************************** 1. row ***************************
    DbName: example_db
    TableName: test_show_tablet
    PartitionName: p20210103
    IndexName: test_show_tablet
    DbId: 11145
    TableId: 9588953
    PartitionId: 9588946
    IndexId: 9588954
    IsSync: true
    DetailCmd: SHOW PROC '/dbs/11145/9588953/partitions/9588946/9588954/9588955';
  • Example 3: Query information of tablets in partition p20210103.

    SHOW TABLET FROM test_show_tablet partition(p20210103);
  • Example 4: Return information of 10 tablets.

        SHOW TABLET FROM test_show_tablet limit 10;
  • Example 5: Return information of 10 tablets with an offset 5.

    SHOW TABLET FROM test_show_tablet limit 5,10;
  • Example 6: Filter tablets by backendid, version, and state.

        SHOW TABLET FROM test_show_tablet
    WHERE backendid = 10004 and version = 1 and state = "NORMAL";
  • Example 7: Sort tablets by version.

        SHOW TABLET FROM table_name where backendid = 10004 order by version;
  • Example 8: Return information of tablets whose index name is test_show_tablet.

    SHOW TABLET FROM test_show_tablet where indexname = "test_show_tablet";